Collision. In this type of boundary, two plates are colliding. This can cause subduction (one plate sliding under the other) or uplift (mountains getting pushed up).

Transform. Here, the two plates are sliding past one another.

Divergent. In this type of boundary, plates are being pushed apart by upwelling magma.

Volcanoes are typically found near collision boundaries where subduction occurs (Japan, for example) or at divergent boundaries. Volcanoes at divergent boundaries are often shield volcanoes. Stratovolcanoes, such as Mt. Rainier and Mt. St. Helens, typically occur near subduction zones.